<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>auto的时候默认为0</title>
	<style>
		.a{
			/*position: relative;*/
			/* 一旦增加了定位信息，就会遮住右侧的图片*/
		}
		.b {
			margin-left: -100px;
		}
	</style>
</head>
<body>
<img src="../image/星空.jpg" alt="" class="a">
<img src="../image/星空.jpg" alt="" class="b">
</body>
</html>